Land mine



' p 1969 1 F. R. SKINNER 11 3,464,354

LAND MINE Filed Nov. 29. 1966 FIG.4

Frank R. Skinner IL,

1NVENTOR.

'FIG. 3 ay Ab "United States Patent 3,464,354 LAND MINE Frank R. Skinner II, Atlanta, Ga., assignor to the United States of America as represented by the Secretary of the Army Filed Nov. 29, 1966, Ser. No. 597,806 Int. Cl. F4211 23/12 US. Cl. 1028 2 Claims ABSTRACT OF THE DISCLOSURE An explosive device which detonates when a pressure system is ruptured. A cartridge disposed adjacent an explosive is detonated by a firing pin disposed on a spring biased piston. When armed, the piston is held away from the cartridge by the force of the pressure system. When unarmed, an annular flexible lip disposed about the firing pin maintains a safe spaced relation between the firing pin and the cartridge.

This invention relates to land mines and in particular to land mines wherein detonation occurs when a pressurized tube extending therefrom is ruptured.

Surface land mines are numerous and varied in design. These mines must, however, be embedded just below the surface so as to detect movement overhead from foot soldiers or equipment. Military operations are sometimes hindered by subterranean penetration or seclusion by the foe. Surface mines are useless to combat tunneling beneath them.

After military operations cease, the land mines of the usual type must be sought out, removed and disarmed. Otherwise, they pose a hazard to the residents of the area. Finding, removing, and disarming all land mines after a lengthly engagement is an exhaustive and time consuming operation.

It is, therefore, an object of this invention to provide a land mine that can be installed so as to hinder the enemies use of tunnels.

Another object of this invention is to provide a land mine that will, after a period of time, render itself inactive.

Yet, another object of this invention is to provide a land mine that is difficult to be detected.

Still, another object of this invention is to provide a land mine that is portable and installable with a minimum amount of surface disruption.

The present invention provides a land mine that is easily armed at the time it is placed in the ground. Armament of the land mine is accomplished by placing the tube extending therefrom under a partial vacuum. This causes a piston located within the mine to be drawn into cocked position and held there by the pressure. Puncture or rupture of the tube causes the spring-loaded piston to be released. Located within the piston is a firing pin which strikes a blank cartridge. Firing of the blank cartridge causes the main explosive to detonate.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a top view of the detonator assembly;

FIGURE 2 is a side view of the land mine;

FIGURE 3 is a view showing the land mine properly installed to combat tunneling, a specific use of the invention;

FIGURE 4 shows the pressure sealing tube used near the end of each tube extending from the mine; and

FIGURE 5 is an alternate method of applying pressure to the mine.

FIGURE 3 shows the present invention embedded in the ground. The land mine 2 is cylindrical in shape with a plurality of tubes 4 extending therefrom. This specific use of the present invention shows the mine located deep enough in the soil 5 so as to be in the path of a probable tunnel 6 that the enemy might dig. The tubes extend laterally from the main body of the mine to give broad "coverage of the area with only one mine.

FIGURE 1 shows the detonator assembly 8. Armament of the mine results when one or more of the tubes extending from the mine are put under a partial vacuum. The vacuum results in the lateral movement of piston 10 located in the cartridge housing 12. Located within the side of the piston facing the blank cartridge 14 is a firing pin 16. Loss of the vacuum within the tube causes the piston, biased by spring 18 to oppose the pressure exerted by the vacuum, to return to the original position with such force as to cause the firing pin to strike the blank cartridge. Firing of the blank cartridge in turn detonates the main explosive 20. Firing chamber 22 is shown in the armed position while firing chamber 24 is shown in the disarmed or safe position. The lip 28 of the piston extends forward toward the cartridge enough to prevent the firing pin from resting on the blank cartridge. The firing spring 18 is long enough when in the disarmed position to keep the piston firmly in place. Only a very high G force would cause the piston to move far enough back so as to detonate the cartridge upon its return. The lip is pliable and under the force of the spring in the cocked position shown in firing chamber 22 will be deformed so as to allow the firing pin to strike the blank cartridge causing it to fire.

FIGURE 4 shows a portion of the tubing 4. The tube according to design must be put under a negative pressure to arm the mine. To do this, a hand vacuum pump could be attached thereto by the implanter and the vacuum thus produced. The tube would need to be able to be closed off after put under vacuum. This is accomplished by the placement of a small section of sealing tube 32 near the actuating end of the tube. When this section of the tube collapses, sealing occurs and the mine is armed. The pump is removed and a clamp 34 (FIGURE 2) is placed on the tube.

It is also of interest to note that even the best seals, best surface finishes and the best sealing compounds will not be absolute. After a period of time, the piston will settle against the cartridge housing. This, of course, renders the mine virtually harmless. This time imperfection is desirable because it means that there will be no mines left behind a few years after the military action ceases.

Another desirable characteristic of the present invention is the absence of magnetic parts. This makes it difiicult to detect the presence of the mines. With the development of plastic explosives, there need be very few parts metallic in nature.

An alternate embodiment of the present invention would be to have the tubes enter the cartridge housing 12 of FIGURE 5. Instead of putting the tube under a partial vacuum the tube would be put under a positive pressure. This would force the pistons back away from the cartridges. The device could be put under pressure by a hand pump or by the use of a pressurized container. The pressurized container could be permanently attached to the tubes when armed. This would make the life expectancy of the land mine longer. If a hand pump is used, a clamp or any conventional means for sealing pressurized containers could be used. Detonation would similarly occur when the tubes were disrupted.

There are, of course, many variations of this invention. Insertion of small segments of glass tubing between segments of the tubes would serve as pressure sensitive triggers which could cause detonation of the mine if they are broken. This would make the mine a dual purpose mine. It would be responsive to weight causing the glass to break and to physical rupture of the tubes. The use of the tubes of any length would make it possible to have the mine detonated from some distance away. The tube could be located at the end of a tunnel while the mine could be located at the entrance of the tunnel. This would permit a number of people to enter the tunnel before detonation occurred.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What I claim is:

1. A land mine comprising an explosive; at least one blank cartridge disposed adjacent said explosive; a cylinder; a piston slideably disposed in said cylinder; a spring within said cylinder biasing said piston; a firing pin and a lip, said firing pin being located on a first end of said piston and aligned with said cartridge; said lip being an annular deformable lip disposed on said first end of said piston and about said firing pin; said lip and said firing pin disposed adjacent said cartridge; said biasing spring disposed adjacent a second end of said piston; a length of pressurized tubing communicating with said cylinder for applying a pressure therein; said pressure being applied against said second end of said piston, the position of said piston being maintained by the pressure.

2. A land mine comprising an explosive; at least one blank cartridge disposed adjacent said explosive; a cylinder; a piston slideably disposed in said cylinder; a spring within said cylinder biasing said piston; a firing pin and a lip, said firing pin being located on a first end of said piston and aligned with said cartridge; said lip being an annular deformable lip disposed on said first end of said piston and about said firing pin; said lip and said firing pin disposed adjacent said cartridge; said biasing spring disposed adjacent a second end of said piston; a length of pressurized tubing communicating with said cylinder for applying a pressure therein; said pressure being applied against said first end of said piston, the position of said piston being maintained by the pressure.

References Cited UNITED STATES PATENTS 1,745,759 2/1930 Gruber 102-8 X 2,438,307 3/1938 Taylor 102-8 2,377,174 5/1945 Parker 102-8 2,415,803 2/1947 Abell 102-45 2,843,042 7/1958 Lazari 102-8 3,221,657 12/ 1965 M-adlener et a1. 102-70 3,266,372 8/1966 Mack et al 89-15 3,288,067 11/1966 Madlener et a1 102-8 X FOREIGN PATENTS 1,074,630 4/ 1954 France. 1,200,516 6/ 1959 France.

SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R. 

